Feasibility of predicting the outcome of fetal infection with cytomegalovirus at the time of prenatal diagnosis

Antenatal treatment options for primary cytomegalovirus infections

PURPOSE OF REVIEW

Cytomegalovirus (CMV) infection is by far the most common fetal viral infection. It carries a risk of long-term sequelae for the neonate; though the severity depends on the gestational age at the time of infection. Improvement in primary prevention of a CMV infection during pregnancy can be achieved by providing information regarding hygiene to the mother. Once a maternal infection occurs, treatment options include prevention of maternal-fetal transmission and, once transmission occurs, attempts to reduce the severity of its effect on the fetus.

RECENT FINDINGS

Several recent studies have shown that providing detailed information regarding the effects of CMV on the fetus and providing common sense hygiene advice reduced new primary infections by more than 75%. In cases with a documented maternal primary CMV infection, treatment with intravenous immunoglobulins have been tried to reduce maternal fetal transmission with a variable degree of success. In the randomized controlled study of Revello et al., immunoglobulins did not reduce the transmission rate. In a recent study, immunoglobulins were given only to women with very recent first trimester infections. In this study, the transmission rate was 2.5%, which is significantly less than expected. Leruez-Ville et al. treated mothers with known transmission of CMV to the fetus with 8 g of valaciclovir daily. They observed a significant reduction in the number of neonatal symptoms in the treated cases.

SUMMARY

Protocols are available to prevent primary CMV infections during pregnancy and, in cases where an infection does occur, steps can be taken to reduce its effect on the fetus thereby reducing the chance of long-term sequelae.

Diagnostic challenges in congenital cytomegalovirus infection in pregnancy: A case report

Cytomegalovirus is the most common congenital viral infection. Infection can cause developmental delay, sensorineural deafness and fetal death. Fetal damage is more severe when infection occurs in the first trimester of pregnancy. Prenatal ultrasound findings may be cerebral, such as ventriculomegaly, microcephaly and periventricular leukomalacia, as well as non-cerebral, such as echogenic bowel, ascites and pericardial effusion. We present a case of congenital cytomegalovirus infection in which the only ultrasound sign noted at routine second-trimester scan was low-grade echogenic bowel, a soft marker, which progressed to severe disease in the third trimester, when further investigation was prompted, leading to the diagnosis. Patients need to be counselled regarding the possible perinatal prognosis. Ultrasound markers can often but not always predict severity and, hence, counselling can be a challenge.

Conclusion: A meticulous anatomy survey in mid-trimester remains the norm and ultrasound soft markers should prompt comprehensive testing for viral infections in pregnancy.

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Fetal damage caused by infection with CMV is more severe when the infection occurs in the first trimester of pregnancy.

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CMV is the most common congenital viral infection causingdevelopmental delay, sensorineural deafness and fetal death.

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Ultrasound markers can often but not always predict the severity of congenital infection.

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A meticulous anatomy survey in mid-trimester remains the norm.

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Ultrasound soft markers should prompt comprehensive testing for viral infections in pregnancy.

Splenic artery blood flow as a potential marker for materno-fetal transmission of a primary CMV infection

OBJECTIVE

To examine the blood flow in the splenic artery as marker for materno-fetal transmission at about 20 weeks following a maternal first-trimester primary CMV infection.

METHODS

This is a retrospective study at the prenatal medicine unit at University of Tuebingen, Germany. Women were included who underwent an amniocentesis to examine the fetal infection status following a maternal primary CMV infection in the first trimester. In all cases, amniocentesis was done at about 20 weeks and at least 6 weeks after the maternal infection. As part of the detailed ultrasound examination prior to each amniocentesis, we examined the peak systolic velocity flow (PSV) and the pulsatility index (PI) of the splenic artery. Measurements were transformed into MoMs according to the normal curves of Ebbing et al. RESULTS: 81 Women fulfilled the inclusion criteria. Maternal and gestational age was 31.9 years and 20.6 weeks' gestation. Maternal-fetal transmission occurred in 13 of the cases. In fetuses without and with a CMV infection, mean PI was 0.98 MoM and 0.89 (p = 0.081). Mean PSV was significantly higher in the group of infected fetuses than in those without (1.24 vs. 0.94 MoM, p = 0.026).

CONCLUSION

The PSV may be a marker for maternal-fetal CMV transmission following a first-trimester maternal infection.

Maternal-fetal transmission and adverse perinatal outcomes in pregnant women infected with Zika virus: prospective cohort study in French Guiana

OBJECTIVES

To estimate the rates of maternal-fetal transmission of Zika virus, adverse fetal/neonatal outcomes, and subsequent rates of asymptomatic/symptomatic congenital Zika virus infections up to the first week of life.

DESIGN

Cohort study with prospective data collection and subsequent review of fetal/neonatal outcomes.

SETTINGS

Referral centre for prenatal diagnosis of the French Guiana Western Hospital.

PARTICIPANTS

Pregnant women at any stage of pregnancy with a laboratory confirmed symptomatic or asymptomatic Zika virus infection during the epidemic period in western French Guiana. The cohort enrolled 300 participants and prospectively followed their 305 fetuses/newborns.

MAIN OUTCOME MEASURES

Rate of maternal-fetal transmission of Zika virus (amniotic fluid, fetal and neonatal blood, urine, cerebrospinal fluid, and placentas); clinical, biological, and radiological outcomes (blindly reviewed); and adverse outcomes defined as moderate signs potentially related to congenital Zika syndrome (CZS), severe complications compatible with CZS, or fetal loss. Associations between a laboratory confirmed congenital Zika virus infection and adverse fetal/neonatal outcomes were evaluated.

RESULTS

Maternal-fetal transmission was documented in 26% (76/291) of fetuses/newborns with complete data. Among the Zika virus positive fetuses/newborns, 45% (34/76) presented with no signs/complications at birth, 20% (15/76) with moderate signs potentially related to CZS, 21% (16/76) with severe complications compatible with CZS, and 14% (11/76) with fetal loss. Compared with the Zika virus positive fetuses/neonates, those that were identified as negative for Zika virus (215/291) were less likely to present with severe complications (5%; 10/215) or fetal loss (0.5%; 1/215; relative risk 6.9, 95% confidence interval 3.6 to 13.3). Association between a positive Zika virus test and any adverse fetal/neonatal outcome was also significant (relative risk 4.4, 2.9 to 6.6). The population attributable fraction estimates that a confirmed congenital Zika virus infection contributes to 47% of adverse outcomes and 61% of severe adverse outcomes observed.

CONCLUSION

In cases of a known maternal Zika virus infection, approximately a quarter of fetuses will become congenitally infected, of which a third will have severe complications at birth or fetal loss. The burden of CZS might be lower than initially described in South America and may not differ from other congenital infections.

[A review on the prevention and treatment of congenital cytomegalovirus infection in mothers and infants]

Human cytomegalovirus (HCMV) has a high infection rate worldwide, and 85%-90% of congenital cytomegalovirus (CMV) infections are asymptomatic at birth, with the clinical manifestations of hearing loss, psychomotor retardation, and learning disabilities, while 10%-15% are symptomatic infections. Some preterm infants develop CMV infection after birth, which can cause sepsis-like syndrome, thrombocytopenia, neutropenia, liver injury, and lung injury. However at present, women of childbearing age have a lack of awareness of CMV. CMV education and hygiene precautions for pregnant women can prevent CMV infections in themselves and congenital CMV infections in their infants. No definite results have been obtained from the studies on the effect of CMV vaccine and high-titer immunoglobulin in preventing congenital CMV infection in fetuses. Recent studies have confirmed that the specificity and sensitivity of urinary or salivary CMV-DNA detection have reached more than 98%, which contributes to the early diagnosis of congenital CMV infection. In addition to short-term treatment with ganciclovir, long-term treatment with oral valganciclovir is safe for symptomatic congenital CMV infection and appears to have a better clinical effect than the short-term treatment. In the future, it is necessary to strengthen the health education for pregnant women, enhance the mother-to-child management of CMV infection, conduct the research on CMV vaccine, and further standardize treatment regimens.

Comparison of quantitative real-time PCR and short-term (18-hour) microculture in diagnosis of fetal cytomegalovirus infection: Impact of hyperimmunoglobulin treatment

OBJECTIVE

The prognostic value of human cytomegalovirus detection (HCMV) DNA levels from amniotic fluid (AF) for the outcome of the infected newborn is still a matter of debate, especially if the onset of maternal primary infection at amniocentesis is unknown. The objective of this study was to investigate the analytical performance in short-term (18-hour) microculture from preconcentrated samples and quantitative real-time PCR (rtPCR) for diagnosis of fetal HCMV infection.

METHODS

A retrospective diagnostic study was conducted on 51 AF samples taken from women that transmitted HCMV prenatally. Amniocentesis was performed around 22-week gestation. The samples were tested for HCMV viral load via quantitative rtPCR and additionally with quantitative short-term (18-hour) microculture following preconcentration via a 50 000 g centrifugation step prior to inoculation to fibroblast monolayers.

RESULTS

Both methods show correlating results (ρ = 0.903). In 25 samples, the women received intravenous hyperimmunoglobulin prior to amniocentesis resulting in a lower correlation of both quantitative methods (ρ = 0.445), in reduced median copy numbers of HCMV DNA (P = .037) and reduced viral infectivity in short-term microculture (P = .025).

CONCLUSION

Both methods lead to correlating results using AF samples from HIG-naïve women. Human cytomegalovirus viral load and infectivity in cell culture are reduced in samples following maternal hyperimmunoglobulin treatment.

Maternal and fetal cytomegalovirus infection: diagnosis, management, and prevention

Congenital cytomegalovirus infection is a major cause of central nervous system and sensory impairments that affect cognition, motor function, hearing, language development, vestibular function, and vision. Although the importance of congenital cytomegalovirus infection is readily evident, the vast majority of maternal and fetal infections are not identified, even in developed countries. Multiple studies of prenatal cytomegalovirus infections have produced a body of knowledge that can inform the clinical approach to suspected or proven maternal and fetal infection. Reliable diagnosis of cytomegalovirus infection during pregnancy and accurate diagnosis of fetal infection are a reality. Approaches to preventing the transmission of cytomegalovirus from mother to fetus and to the treatment of fetal infection are being studied. There is evidence that public health approaches based on hygiene can dramatically reduce the rate of primary maternal cytomegalovirus infections during pregnancy. This review will consider the epidemiology of congenital cytomegalovirus infection, the diagnosis and management of primary infection during pregnancy, and approaches to preventing maternal infection.

Congenital cytomegalovirus infection: management update

PURPOSE OF REVIEW

Until recently, management options in congenital cytomegalovirus (cCMV) infection have been either conservative or termination of pregnancy. However, medical therapies aimed at reducing the risk of infection and/or its severity have recently been investigated.

RECENT FINDINGS

In a phase 2 open label, nonrandomized trial, valaciclovir (ValACV) was given to women carrying a CMV-infected fetus. ValACV was associated with a greater proportion of asymptomatic neonates when compared with a historical cohort (82 vs. 43%). However, the study design and the small number of treated women limit its applicability. Even though initial observational data suggested that hyperimmune globulin (HIG) therapy in pregnancy was associated with a significantly lower risk of cCMV, its efficacy has not been borne out in a subsequent phase 2 randomized, placebo controlled, double-blind study [cCMV 30% in the HIG group, 44% in the placebo group (P = 0.13)]. Furthermore, 11% of fetuses in the HIG group had transient or permanent abnormalities, compared with 16% in the placebo group.

SUMMARY

ValACV might have a promising role in the antenatal treatment of cCMV infection, but definitive recommendations require further research. The use of HIG should currently be limited to the research setting.Video abstract http://links.lww.com/COID/A18.

Prenatal diagnosis of congenital cytomegalovirus infection in 115 cases: a 5 years' single center experience

OBJECTIVE

The objective of this study is to investigate the diagnostic value of invasive prenatal diagnosis (PD) of congenital cytomegalovirus (CMV) infection from amniotic fluid (AF) and fetal blood (FB).

METHODS

A retrospective study was conducted on 115 pregnancies with CMV primary infection. A total of 111 AF and 106 FB samples were investigated for various virological and non-virological markers. Detailed ultrasound examinations were performed at time of PD.

RESULTS

Overall sensitivity of CMV PCR in FB (75.6%; 95%CI 60-87) and AF (72.7%; 95%CI 57-85) was comparable. In women with amniocentesis >8 weeks between seroconversion and PD, we did not observe significant differences between amniocentesis performed ≥17 + 0 (sensitivity 90.9%; 95%CI 71-99) and ≥20 + 0 gestational weeks (sensitivity 90.0%; 95%CI 68-99). Virological markers in FB were higher in symptomatic compared with asymptomatic fetuses (p < 0.05). No significant differences were observed for non-virological markers. However, platelet counts <120 × 10e9/L and beta-2 microglobulin values >14 mg/L were more frequently found in fetuses with severe ultrasound abnormalities compared with fetuses with no or mild abnormalities (p < 0.001).

CONCLUSION

Optimal timing of amniocentesis in women with primary infection in early gestation should be reevaluated in a prospective study. Analysis of FB markers may be beneficial in the individual management of pregnant women with confirmed congenital CMV infection. © 2017 John Wiley & Sons, Ltd.

Congenital cytomegalovirus infection in pregnancy and the neonate: consensus recommendations for prevention, diagnosis, and therapy

Congenital cytomegalovirus is the most frequent, yet under-recognised, infectious cause of newborn malformation in developed countries. Despite its clinical and public health importance, questions remain regarding the best diagnostic methods for identifying maternal and neonatal infection, and regarding optimal prevention and therapeutic strategies for infected mothers and neonates. The absence of guidelines impairs global efforts to decrease the effect of congenital cytomegalovirus. Data in the literature suggest that congenital cytomegalovirus infection remains a research priority, but data are yet to be translated into clinical practice. An informal International Congenital Cytomegalovirus Recommendations Group was convened in 2015 to address these questions and to provide recommendations for prevention, diagnosis, and treatment. On the basis of consensus discussions and a review of the literature, we do not support universal screening of mothers and the routine use of cytomegalovirus immunoglobulin for prophylaxis or treatment of infected mothers. However, treatment guidelines for infected neonates were recommended. Consideration must be given to universal neonatal screening for cytomegalovirus to facilitate early detection and intervention for sensorineural hearing loss and developmental delay, where appropriate. The group agreed that education and prevention strategies for mothers were beneficial, and that recommendations will need continual updating as further data become available.

Primary Human Cytomegalovirus (HCMV) Infection in Pregnancy

BACKGROUND

In 0.5-4% of pregnancies, the prospective mother sustains a primary infection with human cytomegalovirus (HCMV). An HCMV infection of the fetus in the first or second trimester can cause complex post-encephalitic impairment of the infant brain, leading to motor and mental retardation, cerebral palsy, epilepsy, retinal defects, and progressive hearing loss.

METHODS

This review is based on pertinent publications from January 2000 to October 2016 that were retrieved by a selective search in PubMed employing the terms "cytomegalovirus and pregnancy" and "congenital cytomegalovirus."

RESULTS

85-90% of all neonates with HCMV infection are asymptomatic at birth. The main long-term sequela is hearing impairment, which develops in 8-15% of these affected children. Hygienic measures can lower the risk of primary HCMV infection in pregnancy by 50-85%. The first randomized and controlled trial (RCT) of passive immunization with an HCMV-specific hyper - immune globulin (HIG) preparation revealed a trend toward a lower risk of congenital transmission of the virus (30% versus 44% with placebo, p = 0.13). The effect of HIG was more marked in the initial non-randomized trial (15% versus 40%, p = 0.02). The RCT also showed HIG to be associated with a higher frequency of fetal growth retardation and premature birth (13% versus 2%, p = 0.06). Valaciclovir is a further, non-approved treatment option.

CONCLUSION

In the absence of an active vaccine against HCMV, counseling about hygienic measures may currently be the single most effective way to prevent congenital HCMV infection. Moreover, HCMV serologic testing is recommended in the guideline of the Association of the Scientific Medical Societies in Germany (Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften, AWMF). Further randomized trials of treatment with HIG and with valaciclovir are urgently needed so that the options for the prevention and treatment of congenital HCMV infection can be assessed.

Testing for Cytomegalovirus in Pregnancy

Congenital cytomegalovirus (CMV) infection represents a relevant cause of deafness and neurological damage in newborns. Intrauterine CMV transmission might result after primary or nonprimary infections, though at different rates (30% versus 0.2%, respectively). At present, a prenatal diagnosis of CMV infection is based mainly on maternal serology, the detection of CMV-DNA in amniotic fluid and fetal blood, and ultrasound (US) and magnetic resonance imaging (MRI). Recent evidences suggest that congenital CMV infection may be an immune-mediated disease and that evaluation of humoral and especially T-cell immunities may improve the overall prenatal diagnosis. This review summarizes the most recent advancements in the diagnosis of maternal and prenatal CMV infections.

Fetal cytomegalovirus infection

Cytomegalovirus (CMV) congenital infection affects 0.7% of live births worldwide and is the leading cause of congenital neurological handicap of infectious origin. However, systematic screening for this infection has not been implemented in pregnancy or at birth in any country. This apparent paradox had been justified by persisting gaps in the knowledge of this congenital infection: uncertain epidemiological data, difficulty in the diagnosis of maternal infection, absence of validated prenatal prognostic markers, unavailability of an efficient vaccine and scarcity of data available on the treatment. However, in the last decade, new data have emerged towards better management of this congenital infection, including solid epidemiological data, good evidence for the accuracy of diagnosis of maternal CMV infection and good evidence for the feasibility of predicting the outcome of fetal infection by a combination of fetal imaging and fetal laboratory parameters. There is also some evidence that valaciclovir treatment of mothers carrying an infected fetus is feasible, safe and might be effective. This review provides an update on the evidence for diagnosis, prognosis and treatment of congenital infection in the antenatal period. These suggest a benefit to a proactive approach for prenatal congenital infections.

Congenital Cytomegalovirus Infection: Prognostic Value of Maternal DNAemia at Amniocentesis

BACKGROUND

Human Cytomegalovirus (HCMV) is the most common cause of childhood hearing loss and can lead to neurodevelopmental delay. To date, few studies have examined the correlation between maternal viremia and congenital HCMV infection. The aim of our study was to ascertain if HCMV DNA in the peripheral blood of pregnant women with primary HCMV infection at the time of amniocentesis may have a prognostic value in terms of congenital infection and neonatal symptomatic disease.

METHODS

We performed a prospective observational study of pregnant women referred to our maternal-fetal medicine division with suspected HCMV infection. Primary infection was diagnosed based on seroconversion for HCMV and/or HCMV immunoglobulin M-positive and low or moderate HCMV immunoglobulin G avidity. At the time of amniocentesis, maternal blood samples were collected and analyzed by means of real-time polymerase chain reaction to determine the presence of viral DNAemia. Fetuses and newborns were evaluated for the presence of congenital infection and symptomatic disease.

RESULTS

A total of 239 pregnant women were enrolled; 32 blood samples (13.4%) were positive, and 207 (86.6%) were negative for HCMV DNA. The overall rate of transmission was 23.4%. Fifteen infected patients (26.8%) were symptomatic. Vertical transmission occurred in 14 women (43.8%) with positive and 42 (20.3%) with negative results for HCMV DNAemia (P = .006; odds ratio, 3.06; 95% confidence interval, 1.41-6.64). Symptomatic infection occurred in 6 (42.9%) infected fetuses or newborns from women with and in 9 (21.4%) from women without viral DNAemia (P = .16).

CONCLUSION

Maternal viremia at amniocentesis is associated with a 3-fold greater chance of congenital infection, but it is not correlated with symptomatic disease.

Study of Soluble HLA-G in Congenital Human Cytomegalovirus Infection

Human leukocyte antigen-G (HLA-G) is a nonclassical HLA class I antigen that is expressed during pregnancy contributing to maternal-fetal tolerance. HLA-G can be expressed as membrane-bound and soluble forms. HLA-G expression increases strongly during viral infections such as congenital human cytomegalovirus (HCMV) infections, with functional consequences in immunoregulation. In this work we investigated the expression of soluble (s)HLA-G and beta-2 microglobulin (component of HLA) molecules in correlation with the risk of transmission and severity of congenital HCMV infection. We analyzed 182 blood samples from 130 pregnant women and 52 nonpregnant women and 56 amniotic fluid samples from women experiencing primary HCMV infection. The median levels of sHLA-G in maternal serum of women with primary HCMV infection were higher in comparison with nonprimary and uninfected pregnant women (p < 0.001). AF from HCMV symptomatic fetuses presented higher sHLA-G levels in comparison with infected asymptomatic fetuses (p < 0.001), presence of HLA-G free-heavy chain, and a concentration gradient from amniotic fluid to maternal blood. No significant statistical difference of beta-2 microglobulin median levels was observed between all different groups. Our results suggest the determination of sHLA-G molecules in both maternal blood and amniotic fluid as a promising biomarker of diagnosis of maternal HCMV primary infection and fetal HCMV disease.